1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Translate the completed AST to the LLVM IR.
13 //! Some functions here, such as trans_block and trans_expr, return a value --
14 //! the result of the translation to LLVM -- while others, such as trans_fn
15 //! and trans_item, are called only for the side effect of adding a
16 //! particular definition to the LLVM IR output we're producing.
18 //! Hopefully useful general knowledge about trans:
20 //! * There's no way to find out the Ty type of a ValueRef. Doing so
21 //! would be "trying to get the eggs out of an omelette" (credit:
22 //! pcwalton). You can, instead, find out its TypeRef by calling val_ty,
23 //! but one TypeRef corresponds to many `Ty`s; for instance, tup(int, int,
24 //! int) and rec(x=int, y=int, z=int) will have the same TypeRef.
26 use super::CrateTranslation;
27 use super::ModuleLlvm;
28 use super::ModuleSource;
29 use super::ModuleTranslation;
31 use assert_module_sources;
33 use back::linker::LinkerInfo;
34 use back::symbol_export::{self, ExportedSymbols};
35 use llvm::{ContextRef, Linkage, ModuleRef, ValueRef, Vector, get_param};
38 use rustc::hir::def_id::LOCAL_CRATE;
39 use middle::lang_items::StartFnLangItem;
40 use middle::cstore::EncodedMetadata;
41 use rustc::ty::{self, Ty, TyCtxt};
42 use rustc::dep_graph::AssertDepGraphSafe;
43 use rustc::middle::cstore::LinkMeta;
44 use rustc::hir::map as hir_map;
45 use rustc::util::common::time;
46 use session::config::{self, NoDebugInfo};
47 use rustc_incremental::IncrementalHashesMap;
48 use session::{self, DataTypeKind, Session};
50 use mir::lvalue::LvalueRef;
54 use common::{C_bool, C_bytes_in_context, C_i32, C_uint};
55 use collector::{self, TransItemCollectionMode};
56 use common::{C_struct_in_context, C_u64, C_undef, C_array};
57 use common::CrateContext;
58 use common::{type_is_zero_size, val_ty};
61 use context::{self, LocalCrateContext, SharedCrateContext, Stats};
67 use monomorphize::{self, Instance};
68 use partitioning::{self, PartitioningStrategy, CodegenUnit};
69 use symbol_names_test;
70 use trans_item::{TransItem, DefPathBasedNames};
74 use util::nodemap::{NodeSet, FxHashMap, FxHashSet};
77 use std::ffi::{CStr, CString};
83 use rustc::ty::layout::{self, Layout};
86 use mir::lvalue::Alignment;
88 pub struct StatRecorder<'a, 'tcx: 'a> {
89 ccx: &'a CrateContext<'a, 'tcx>,
94 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
95 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String) -> StatRecorder<'a, 'tcx> {
96 let istart = ccx.stats().n_llvm_insns.get();
105 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
107 if self.ccx.sess().trans_stats() {
108 let iend = self.ccx.stats().n_llvm_insns.get();
109 self.ccx.stats().fn_stats.borrow_mut()
110 .push((self.name.take().unwrap(), iend - self.istart));
111 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
112 // Reset LLVM insn count to avoid compound costs.
113 self.ccx.stats().n_llvm_insns.set(self.istart);
118 pub fn get_meta(bcx: &Builder, fat_ptr: ValueRef) -> ValueRef {
119 bcx.struct_gep(fat_ptr, abi::FAT_PTR_EXTRA)
122 pub fn get_dataptr(bcx: &Builder, fat_ptr: ValueRef) -> ValueRef {
123 bcx.struct_gep(fat_ptr, abi::FAT_PTR_ADDR)
126 pub fn bin_op_to_icmp_predicate(op: hir::BinOp_,
128 -> llvm::IntPredicate {
130 hir::BiEq => llvm::IntEQ,
131 hir::BiNe => llvm::IntNE,
132 hir::BiLt => if signed { llvm::IntSLT } else { llvm::IntULT },
133 hir::BiLe => if signed { llvm::IntSLE } else { llvm::IntULE },
134 hir::BiGt => if signed { llvm::IntSGT } else { llvm::IntUGT },
135 hir::BiGe => if signed { llvm::IntSGE } else { llvm::IntUGE },
137 bug!("comparison_op_to_icmp_predicate: expected comparison operator, \
144 pub fn bin_op_to_fcmp_predicate(op: hir::BinOp_) -> llvm::RealPredicate {
146 hir::BiEq => llvm::RealOEQ,
147 hir::BiNe => llvm::RealUNE,
148 hir::BiLt => llvm::RealOLT,
149 hir::BiLe => llvm::RealOLE,
150 hir::BiGt => llvm::RealOGT,
151 hir::BiGe => llvm::RealOGE,
153 bug!("comparison_op_to_fcmp_predicate: expected comparison operator, \
160 pub fn compare_simd_types<'a, 'tcx>(
161 bcx: &Builder<'a, 'tcx>,
168 let signed = match t.sty {
170 let cmp = bin_op_to_fcmp_predicate(op);
171 return bcx.sext(bcx.fcmp(cmp, lhs, rhs), ret_ty);
173 ty::TyUint(_) => false,
174 ty::TyInt(_) => true,
175 _ => bug!("compare_simd_types: invalid SIMD type"),
178 let cmp = bin_op_to_icmp_predicate(op, signed);
179 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
180 // to get the correctly sized type. This will compile to a single instruction
181 // once the IR is converted to assembly if the SIMD instruction is supported
182 // by the target architecture.
183 bcx.sext(bcx.icmp(cmp, lhs, rhs), ret_ty)
186 /// Retrieve the information we are losing (making dynamic) in an unsizing
189 /// The `old_info` argument is a bit funny. It is intended for use
190 /// in an upcast, where the new vtable for an object will be drived
191 /// from the old one.
192 pub fn unsized_info<'ccx, 'tcx>(ccx: &CrateContext<'ccx, 'tcx>,
195 old_info: Option<ValueRef>)
197 let (source, target) = ccx.tcx().struct_lockstep_tails(source, target);
198 match (&source.sty, &target.sty) {
199 (&ty::TyArray(_, len), &ty::TySlice(_)) => C_uint(ccx, len),
200 (&ty::TyDynamic(..), &ty::TyDynamic(..)) => {
201 // For now, upcasts are limited to changes in marker
202 // traits, and hence never actually require an actual
203 // change to the vtable.
204 old_info.expect("unsized_info: missing old info for trait upcast")
206 (_, &ty::TyDynamic(ref data, ..)) => {
207 consts::ptrcast(meth::get_vtable(ccx, source, data.principal()),
208 Type::vtable_ptr(ccx))
210 _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}",
216 /// Coerce `src` to `dst_ty`. `src_ty` must be a thin pointer.
217 pub fn unsize_thin_ptr<'a, 'tcx>(
218 bcx: &Builder<'a, 'tcx>,
222 ) -> (ValueRef, ValueRef) {
223 debug!("unsize_thin_ptr: {:?} => {:?}", src_ty, dst_ty);
224 match (&src_ty.sty, &dst_ty.sty) {
225 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
226 &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) |
227 (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }),
228 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) |
229 (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }),
230 &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => {
231 assert!(bcx.ccx.shared().type_is_sized(a));
232 let ptr_ty = type_of::in_memory_type_of(bcx.ccx, b).ptr_to();
233 (bcx.pointercast(src, ptr_ty), unsized_info(bcx.ccx, a, b, None))
235 (&ty::TyAdt(def_a, _), &ty::TyAdt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
236 let (a, b) = (src_ty.boxed_ty(), dst_ty.boxed_ty());
237 assert!(bcx.ccx.shared().type_is_sized(a));
238 let ptr_ty = type_of::in_memory_type_of(bcx.ccx, b).ptr_to();
239 (bcx.pointercast(src, ptr_ty), unsized_info(bcx.ccx, a, b, None))
241 _ => bug!("unsize_thin_ptr: called on bad types"),
245 /// Coerce `src`, which is a reference to a value of type `src_ty`,
246 /// to a value of type `dst_ty` and store the result in `dst`
247 pub fn coerce_unsized_into<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
248 src: &LvalueRef<'tcx>,
249 dst: &LvalueRef<'tcx>) {
250 let src_ty = src.ty.to_ty(bcx.tcx());
251 let dst_ty = dst.ty.to_ty(bcx.tcx());
252 let coerce_ptr = || {
253 let (base, info) = if common::type_is_fat_ptr(bcx.ccx, src_ty) {
254 // fat-ptr to fat-ptr unsize preserves the vtable
255 // i.e. &'a fmt::Debug+Send => &'a fmt::Debug
256 // So we need to pointercast the base to ensure
257 // the types match up.
258 let (base, info) = load_fat_ptr(bcx, src.llval, src.alignment, src_ty);
259 let llcast_ty = type_of::fat_ptr_base_ty(bcx.ccx, dst_ty);
260 let base = bcx.pointercast(base, llcast_ty);
263 let base = load_ty(bcx, src.llval, src.alignment, src_ty);
264 unsize_thin_ptr(bcx, base, src_ty, dst_ty)
266 store_fat_ptr(bcx, base, info, dst.llval, dst.alignment, dst_ty);
268 match (&src_ty.sty, &dst_ty.sty) {
269 (&ty::TyRef(..), &ty::TyRef(..)) |
270 (&ty::TyRef(..), &ty::TyRawPtr(..)) |
271 (&ty::TyRawPtr(..), &ty::TyRawPtr(..)) => {
274 (&ty::TyAdt(def_a, _), &ty::TyAdt(def_b, _)) if def_a.is_box() && def_b.is_box() => {
278 (&ty::TyAdt(def_a, substs_a), &ty::TyAdt(def_b, substs_b)) => {
279 assert_eq!(def_a, def_b);
281 let src_fields = def_a.variants[0].fields.iter().map(|f| {
282 monomorphize::field_ty(bcx.tcx(), substs_a, f)
284 let dst_fields = def_b.variants[0].fields.iter().map(|f| {
285 monomorphize::field_ty(bcx.tcx(), substs_b, f)
288 let iter = src_fields.zip(dst_fields).enumerate();
289 for (i, (src_fty, dst_fty)) in iter {
290 if type_is_zero_size(bcx.ccx, dst_fty) {
294 let (src_f, src_f_align) = src.trans_field_ptr(bcx, i);
295 let (dst_f, dst_f_align) = dst.trans_field_ptr(bcx, i);
296 if src_fty == dst_fty {
297 memcpy_ty(bcx, dst_f, src_f, src_fty, None);
301 &LvalueRef::new_sized_ty(src_f, src_fty, src_f_align),
302 &LvalueRef::new_sized_ty(dst_f, dst_fty, dst_f_align)
307 _ => bug!("coerce_unsized_into: invalid coercion {:?} -> {:?}",
313 pub fn cast_shift_expr_rhs(
314 cx: &Builder, op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef
316 cast_shift_rhs(op, lhs, rhs, |a, b| cx.trunc(a, b), |a, b| cx.zext(a, b))
319 pub fn cast_shift_const_rhs(op: hir::BinOp_, lhs: ValueRef, rhs: ValueRef) -> ValueRef {
323 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
324 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
327 fn cast_shift_rhs<F, G>(op: hir::BinOp_,
333 where F: FnOnce(ValueRef, Type) -> ValueRef,
334 G: FnOnce(ValueRef, Type) -> ValueRef
336 // Shifts may have any size int on the rhs
338 let mut rhs_llty = val_ty(rhs);
339 let mut lhs_llty = val_ty(lhs);
340 if rhs_llty.kind() == Vector {
341 rhs_llty = rhs_llty.element_type()
343 if lhs_llty.kind() == Vector {
344 lhs_llty = lhs_llty.element_type()
346 let rhs_sz = rhs_llty.int_width();
347 let lhs_sz = lhs_llty.int_width();
350 } else if lhs_sz > rhs_sz {
351 // FIXME (#1877: If shifting by negative
352 // values becomes not undefined then this is wrong.
362 /// Returns whether this session's target will use SEH-based unwinding.
364 /// This is only true for MSVC targets, and even then the 64-bit MSVC target
365 /// currently uses SEH-ish unwinding with DWARF info tables to the side (same as
366 /// 64-bit MinGW) instead of "full SEH".
367 pub fn wants_msvc_seh(sess: &Session) -> bool {
368 sess.target.target.options.is_like_msvc
371 pub fn call_assume<'a, 'tcx>(b: &Builder<'a, 'tcx>, val: ValueRef) {
372 let assume_intrinsic = b.ccx.get_intrinsic("llvm.assume");
373 b.call(assume_intrinsic, &[val], None);
376 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
377 /// differs from the type used for SSA values. Also handles various special cases where the type
378 /// gives us better information about what we are loading.
379 pub fn load_ty<'a, 'tcx>(b: &Builder<'a, 'tcx>, ptr: ValueRef,
380 alignment: Alignment, t: Ty<'tcx>) -> ValueRef {
382 if type_is_zero_size(ccx, t) {
383 return C_undef(type_of::type_of(ccx, t));
387 let global = llvm::LLVMIsAGlobalVariable(ptr);
388 if !global.is_null() && llvm::LLVMIsGlobalConstant(global) == llvm::True {
389 let val = llvm::LLVMGetInitializer(global);
392 return llvm::LLVMConstTrunc(val, Type::i1(ccx).to_ref());
400 b.trunc(b.load_range_assert(ptr, 0, 2, llvm::False, alignment.to_align()),
402 } else if t.is_char() {
403 // a char is a Unicode codepoint, and so takes values from 0
404 // to 0x10FFFF inclusive only.
405 b.load_range_assert(ptr, 0, 0x10FFFF + 1, llvm::False, alignment.to_align())
406 } else if (t.is_region_ptr() || t.is_box() || t.is_fn())
407 && !common::type_is_fat_ptr(ccx, t)
409 b.load_nonnull(ptr, alignment.to_align())
411 b.load(ptr, alignment.to_align())
415 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
416 /// differs from the type used for SSA values.
417 pub fn store_ty<'a, 'tcx>(cx: &Builder<'a, 'tcx>, v: ValueRef, dst: ValueRef,
418 dst_align: Alignment, t: Ty<'tcx>) {
419 debug!("store_ty: {:?} : {:?} <- {:?}", Value(dst), t, Value(v));
421 if common::type_is_fat_ptr(cx.ccx, t) {
422 let lladdr = cx.extract_value(v, abi::FAT_PTR_ADDR);
423 let llextra = cx.extract_value(v, abi::FAT_PTR_EXTRA);
424 store_fat_ptr(cx, lladdr, llextra, dst, dst_align, t);
426 cx.store(from_immediate(cx, v), dst, dst_align.to_align());
430 pub fn store_fat_ptr<'a, 'tcx>(cx: &Builder<'a, 'tcx>,
434 dst_align: Alignment,
436 // FIXME: emit metadata
437 cx.store(data, get_dataptr(cx, dst), dst_align.to_align());
438 cx.store(extra, get_meta(cx, dst), dst_align.to_align());
441 pub fn load_fat_ptr<'a, 'tcx>(
442 b: &Builder<'a, 'tcx>, src: ValueRef, alignment: Alignment, t: Ty<'tcx>
443 ) -> (ValueRef, ValueRef) {
444 let ptr = get_dataptr(b, src);
445 let ptr = if t.is_region_ptr() || t.is_box() {
446 b.load_nonnull(ptr, alignment.to_align())
448 b.load(ptr, alignment.to_align())
451 let meta = get_meta(b, src);
452 let meta_ty = val_ty(meta);
453 // If the 'meta' field is a pointer, it's a vtable, so use load_nonnull
455 let meta = if meta_ty.element_type().kind() == llvm::TypeKind::Pointer {
456 b.load_nonnull(meta, None)
464 pub fn from_immediate(bcx: &Builder, val: ValueRef) -> ValueRef {
465 if val_ty(val) == Type::i1(bcx.ccx) {
466 bcx.zext(val, Type::i8(bcx.ccx))
472 pub fn to_immediate(bcx: &Builder, val: ValueRef, ty: Ty) -> ValueRef {
474 bcx.trunc(val, Type::i1(bcx.ccx))
480 pub enum Lifetime { Start, End }
483 // If LLVM lifetime intrinsic support is enabled (i.e. optimizations
484 // on), and `ptr` is nonzero-sized, then extracts the size of `ptr`
485 // and the intrinsic for `lt` and passes them to `emit`, which is in
486 // charge of generating code to call the passed intrinsic on whatever
487 // block of generated code is targetted for the intrinsic.
489 // If LLVM lifetime intrinsic support is disabled (i.e. optimizations
490 // off) or `ptr` is zero-sized, then no-op (does not call `emit`).
491 pub fn call(self, b: &Builder, ptr: ValueRef) {
492 if b.ccx.sess().opts.optimize == config::OptLevel::No {
496 let size = machine::llsize_of_alloc(b.ccx, val_ty(ptr).element_type());
501 let lifetime_intrinsic = b.ccx.get_intrinsic(match self {
502 Lifetime::Start => "llvm.lifetime.start",
503 Lifetime::End => "llvm.lifetime.end"
506 let ptr = b.pointercast(ptr, Type::i8p(b.ccx));
507 b.call(lifetime_intrinsic, &[C_u64(b.ccx, size), ptr], None);
511 pub fn call_memcpy<'a, 'tcx>(b: &Builder<'a, 'tcx>,
517 let ptr_width = &ccx.sess().target.target.target_pointer_width;
518 let key = format!("llvm.memcpy.p0i8.p0i8.i{}", ptr_width);
519 let memcpy = ccx.get_intrinsic(&key);
520 let src_ptr = b.pointercast(src, Type::i8p(ccx));
521 let dst_ptr = b.pointercast(dst, Type::i8p(ccx));
522 let size = b.intcast(n_bytes, ccx.int_type(), false);
523 let align = C_i32(ccx, align as i32);
524 let volatile = C_bool(ccx, false);
525 b.call(memcpy, &[dst_ptr, src_ptr, size, align, volatile], None);
528 pub fn memcpy_ty<'a, 'tcx>(
529 bcx: &Builder<'a, 'tcx>,
537 let size = ccx.size_of(t);
542 let align = align.unwrap_or_else(|| ccx.align_of(t));
543 call_memcpy(bcx, dst, src, C_uint(ccx, size), align);
546 pub fn call_memset<'a, 'tcx>(b: &Builder<'a, 'tcx>,
551 volatile: bool) -> ValueRef {
552 let ptr_width = &b.ccx.sess().target.target.target_pointer_width;
553 let intrinsic_key = format!("llvm.memset.p0i8.i{}", ptr_width);
554 let llintrinsicfn = b.ccx.get_intrinsic(&intrinsic_key);
555 let volatile = C_bool(b.ccx, volatile);
556 b.call(llintrinsicfn, &[ptr, fill_byte, size, align, volatile], None)
559 pub fn trans_instance<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, instance: Instance<'tcx>) {
560 let _s = if ccx.sess().trans_stats() {
561 let mut instance_name = String::new();
562 DefPathBasedNames::new(ccx.tcx(), true, true)
563 .push_def_path(instance.def_id(), &mut instance_name);
564 Some(StatRecorder::new(ccx, instance_name))
569 // this is an info! to allow collecting monomorphization statistics
570 // and to allow finding the last function before LLVM aborts from
572 info!("trans_instance({})", instance);
574 let fn_ty = common::instance_ty(ccx.shared(), &instance);
575 let sig = common::ty_fn_sig(ccx, fn_ty);
576 let sig = ccx.tcx().erase_late_bound_regions_and_normalize(&sig);
578 let lldecl = match ccx.instances().borrow().get(&instance) {
580 None => bug!("Instance `{:?}` not already declared", instance)
583 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
585 // The `uwtable` attribute according to LLVM is:
587 // This attribute indicates that the ABI being targeted requires that an
588 // unwind table entry be produced for this function even if we can show
589 // that no exceptions passes by it. This is normally the case for the
590 // ELF x86-64 abi, but it can be disabled for some compilation units.
592 // Typically when we're compiling with `-C panic=abort` (which implies this
593 // `no_landing_pads` check) we don't need `uwtable` because we can't
594 // generate any exceptions! On Windows, however, exceptions include other
595 // events such as illegal instructions, segfaults, etc. This means that on
596 // Windows we end up still needing the `uwtable` attribute even if the `-C
597 // panic=abort` flag is passed.
599 // You can also find more info on why Windows is whitelisted here in:
600 // https://bugzilla.mozilla.org/show_bug.cgi?id=1302078
601 if !ccx.sess().no_landing_pads() ||
602 ccx.sess().target.target.options.is_like_windows {
603 attributes::emit_uwtable(lldecl, true);
606 let mir = ccx.tcx().instance_mir(instance.def);
607 mir::trans_mir(ccx, lldecl, &mir, instance, sig);
610 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
611 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
612 // applicable to variable declarations and may not really make sense for
613 // Rust code in the first place but whitelist them anyway and trust that
614 // the user knows what s/he's doing. Who knows, unanticipated use cases
615 // may pop up in the future.
617 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
618 // and don't have to be, LLVM treats them as no-ops.
620 "appending" => Some(llvm::Linkage::AppendingLinkage),
621 "available_externally" => Some(llvm::Linkage::AvailableExternallyLinkage),
622 "common" => Some(llvm::Linkage::CommonLinkage),
623 "extern_weak" => Some(llvm::Linkage::ExternalWeakLinkage),
624 "external" => Some(llvm::Linkage::ExternalLinkage),
625 "internal" => Some(llvm::Linkage::InternalLinkage),
626 "linkonce" => Some(llvm::Linkage::LinkOnceAnyLinkage),
627 "linkonce_odr" => Some(llvm::Linkage::LinkOnceODRLinkage),
628 "private" => Some(llvm::Linkage::PrivateLinkage),
629 "weak" => Some(llvm::Linkage::WeakAnyLinkage),
630 "weak_odr" => Some(llvm::Linkage::WeakODRLinkage),
635 pub fn set_link_section(ccx: &CrateContext,
637 attrs: &[ast::Attribute]) {
638 if let Some(sect) = attr::first_attr_value_str_by_name(attrs, "link_section") {
639 if contains_null(§.as_str()) {
640 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`", §));
643 let buf = CString::new(sect.as_str().as_bytes()).unwrap();
644 llvm::LLVMSetSection(llval, buf.as_ptr());
649 /// Create the `main` function which will initialise the rust runtime and call
650 /// users main function.
651 pub fn maybe_create_entry_wrapper(ccx: &CrateContext) {
652 let (main_def_id, span) = match *ccx.sess().entry_fn.borrow() {
653 Some((id, span)) => {
654 (ccx.tcx().hir.local_def_id(id), span)
659 // check for the #[rustc_error] annotation, which forces an
660 // error in trans. This is used to write compile-fail tests
661 // that actually test that compilation succeeds without
662 // reporting an error.
663 if ccx.tcx().has_attr(main_def_id, "rustc_error") {
664 ccx.tcx().sess.span_fatal(span, "compilation successful");
667 let instance = Instance::mono(ccx.tcx(), main_def_id);
669 if !ccx.codegen_unit().contains_item(&TransItem::Fn(instance)) {
670 // We want to create the wrapper in the same codegen unit as Rust's main
675 let main_llfn = callee::get_fn(ccx, instance);
677 let et = ccx.sess().entry_type.get().unwrap();
679 config::EntryMain => create_entry_fn(ccx, span, main_llfn, true),
680 config::EntryStart => create_entry_fn(ccx, span, main_llfn, false),
681 config::EntryNone => {} // Do nothing.
684 fn create_entry_fn(ccx: &CrateContext,
687 use_start_lang_item: bool) {
688 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()], &ccx.int_type());
690 if declare::get_defined_value(ccx, "main").is_some() {
691 // FIXME: We should be smart and show a better diagnostic here.
692 ccx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
693 .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
695 ccx.sess().abort_if_errors();
698 let llfn = declare::declare_cfn(ccx, "main", llfty);
700 // `main` should respect same config for frame pointer elimination as rest of code
701 attributes::set_frame_pointer_elimination(ccx, llfn);
703 let bld = Builder::new_block(ccx, llfn, "top");
705 debuginfo::gdb::insert_reference_to_gdb_debug_scripts_section_global(ccx, &bld);
707 let (start_fn, args) = if use_start_lang_item {
708 let start_def_id = ccx.tcx().require_lang_item(StartFnLangItem);
709 let start_instance = Instance::mono(ccx.tcx(), start_def_id);
710 let start_fn = callee::get_fn(ccx, start_instance);
711 (start_fn, vec![bld.pointercast(rust_main, Type::i8p(ccx).ptr_to()), get_param(llfn, 0),
714 debug!("using user-defined start fn");
715 (rust_main, vec![get_param(llfn, 0 as c_uint), get_param(llfn, 1 as c_uint)])
718 let result = bld.call(start_fn, &args, None);
723 fn contains_null(s: &str) -> bool {
724 s.bytes().any(|b| b == 0)
727 fn write_metadata<'a, 'gcx>(tcx: TyCtxt<'a, 'gcx, 'gcx>,
728 link_meta: &LinkMeta,
729 exported_symbols: &NodeSet)
730 -> (ContextRef, ModuleRef, EncodedMetadata) {
733 let (metadata_llcx, metadata_llmod) = unsafe {
734 context::create_context_and_module(tcx.sess, "metadata")
737 #[derive(PartialEq, Eq, PartialOrd, Ord)]
744 let kind = tcx.sess.crate_types.borrow().iter().map(|ty| {
746 config::CrateTypeExecutable |
747 config::CrateTypeStaticlib |
748 config::CrateTypeCdylib => MetadataKind::None,
750 config::CrateTypeRlib => MetadataKind::Uncompressed,
752 config::CrateTypeDylib |
753 config::CrateTypeProcMacro => MetadataKind::Compressed,
757 if kind == MetadataKind::None {
758 return (metadata_llcx, metadata_llmod, EncodedMetadata::new());
761 let cstore = &tcx.sess.cstore;
762 let metadata = cstore.encode_metadata(tcx,
765 if kind == MetadataKind::Uncompressed {
766 return (metadata_llcx, metadata_llmod, metadata);
769 assert!(kind == MetadataKind::Compressed);
770 let mut compressed = cstore.metadata_encoding_version().to_vec();
771 compressed.extend_from_slice(&flate::deflate_bytes(&metadata.raw_data));
773 let llmeta = C_bytes_in_context(metadata_llcx, &compressed);
774 let llconst = C_struct_in_context(metadata_llcx, &[llmeta], false);
775 let name = symbol_export::metadata_symbol_name(tcx);
776 let buf = CString::new(name).unwrap();
777 let llglobal = unsafe {
778 llvm::LLVMAddGlobal(metadata_llmod, val_ty(llconst).to_ref(), buf.as_ptr())
781 llvm::LLVMSetInitializer(llglobal, llconst);
782 let section_name = metadata::metadata_section_name(&tcx.sess.target.target);
783 let name = CString::new(section_name).unwrap();
784 llvm::LLVMSetSection(llglobal, name.as_ptr());
786 // Also generate a .section directive to force no
787 // flags, at least for ELF outputs, so that the
788 // metadata doesn't get loaded into memory.
789 let directive = format!(".section {}", section_name);
790 let directive = CString::new(directive).unwrap();
791 llvm::LLVMSetModuleInlineAsm(metadata_llmod, directive.as_ptr())
793 return (metadata_llcx, metadata_llmod, metadata);
796 /// Find any symbols that are defined in one compilation unit, but not declared
797 /// in any other compilation unit. Give these symbols internal linkage.
798 fn internalize_symbols<'a, 'tcx>(sess: &Session,
799 scx: &SharedCrateContext<'a, 'tcx>,
800 translation_items: &FxHashSet<TransItem<'tcx>>,
801 llvm_modules: &[ModuleLlvm],
802 exported_symbols: &ExportedSymbols) {
803 let export_threshold =
804 symbol_export::crates_export_threshold(&sess.crate_types.borrow());
806 let exported_symbols = exported_symbols
807 .exported_symbols(LOCAL_CRATE)
809 .filter(|&&(_, export_level)| {
810 symbol_export::is_below_threshold(export_level, export_threshold)
812 .map(|&(ref name, _)| &name[..])
813 .collect::<FxHashSet<&str>>();
817 let incr_comp = sess.opts.debugging_opts.incremental.is_some();
819 // 'unsafe' because we are holding on to CStr's from the LLVM module within
822 let mut referenced_somewhere = FxHashSet();
824 // Collect all symbols that need to stay externally visible because they
825 // are referenced via a declaration in some other codegen unit. In
826 // incremental compilation, we don't need to collect. See below for more
829 for ll in llvm_modules {
830 for val in iter_globals(ll.llmod).chain(iter_functions(ll.llmod)) {
831 let linkage = llvm::LLVMRustGetLinkage(val);
832 // We only care about external declarations (not definitions)
833 // and available_externally definitions.
834 let is_available_externally =
835 linkage == llvm::Linkage::AvailableExternallyLinkage;
836 let is_decl = llvm::LLVMIsDeclaration(val) == llvm::True;
838 if is_decl || is_available_externally {
839 let symbol_name = CStr::from_ptr(llvm::LLVMGetValueName(val));
840 referenced_somewhere.insert(symbol_name);
846 // Also collect all symbols for which we cannot adjust linkage, because
847 // it is fixed by some directive in the source code.
848 let (locally_defined_symbols, linkage_fixed_explicitly) = {
849 let mut locally_defined_symbols = FxHashSet();
850 let mut linkage_fixed_explicitly = FxHashSet();
852 for trans_item in translation_items {
853 let symbol_name = str::to_owned(&trans_item.symbol_name(tcx));
854 if trans_item.explicit_linkage(tcx).is_some() {
855 linkage_fixed_explicitly.insert(symbol_name.clone());
857 locally_defined_symbols.insert(symbol_name);
860 (locally_defined_symbols, linkage_fixed_explicitly)
863 // Examine each external definition. If the definition is not used in
864 // any other compilation unit, and is not reachable from other crates,
865 // then give it internal linkage.
866 for ll in llvm_modules {
867 for val in iter_globals(ll.llmod).chain(iter_functions(ll.llmod)) {
868 let linkage = llvm::LLVMRustGetLinkage(val);
870 let is_externally_visible = (linkage == llvm::Linkage::ExternalLinkage) ||
871 (linkage == llvm::Linkage::LinkOnceODRLinkage) ||
872 (linkage == llvm::Linkage::WeakODRLinkage);
874 if !is_externally_visible {
875 // This symbol is not visible outside of its codegen unit,
876 // so there is nothing to do for it.
880 let name_cstr = CStr::from_ptr(llvm::LLVMGetValueName(val));
881 let name_str = name_cstr.to_str().unwrap();
883 if exported_symbols.contains(&name_str) {
884 // This symbol is explicitly exported, so we can't
885 // mark it as internal or hidden.
889 let is_declaration = llvm::LLVMIsDeclaration(val) == llvm::True;
892 if locally_defined_symbols.contains(name_str) {
893 // Only mark declarations from the current crate as hidden.
894 // Otherwise we would mark things as hidden that are
895 // imported from other crates or native libraries.
896 llvm::LLVMRustSetVisibility(val, llvm::Visibility::Hidden);
899 let has_fixed_linkage = linkage_fixed_explicitly.contains(name_str);
901 if !has_fixed_linkage {
902 // In incremental compilation mode, we can't be sure that
903 // we saw all references because we don't know what's in
904 // cached compilation units, so we always assume that the
905 // given item has been referenced.
906 if incr_comp || referenced_somewhere.contains(&name_cstr) {
907 llvm::LLVMRustSetVisibility(val, llvm::Visibility::Hidden);
909 llvm::LLVMRustSetLinkage(val, llvm::Linkage::InternalLinkage);
912 llvm::LLVMSetDLLStorageClass(val, llvm::DLLStorageClass::Default);
913 llvm::UnsetComdat(val);
921 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
922 // This is required to satisfy `dllimport` references to static data in .rlibs
923 // when using MSVC linker. We do this only for data, as linker can fix up
924 // code references on its own.
925 // See #26591, #27438
926 fn create_imps(sess: &Session,
927 llvm_modules: &[ModuleLlvm]) {
928 // The x86 ABI seems to require that leading underscores are added to symbol
929 // names, so we need an extra underscore on 32-bit. There's also a leading
930 // '\x01' here which disables LLVM's symbol mangling (e.g. no extra
931 // underscores added in front).
932 let prefix = if sess.target.target.target_pointer_width == "32" {
938 for ll in llvm_modules {
939 let exported: Vec<_> = iter_globals(ll.llmod)
941 llvm::LLVMRustGetLinkage(val) ==
942 llvm::Linkage::ExternalLinkage &&
943 llvm::LLVMIsDeclaration(val) == 0
947 let i8p_ty = Type::i8p_llcx(ll.llcx);
948 for val in exported {
949 let name = CStr::from_ptr(llvm::LLVMGetValueName(val));
950 let mut imp_name = prefix.as_bytes().to_vec();
951 imp_name.extend(name.to_bytes());
952 let imp_name = CString::new(imp_name).unwrap();
953 let imp = llvm::LLVMAddGlobal(ll.llmod,
955 imp_name.as_ptr() as *const _);
956 let init = llvm::LLVMConstBitCast(val, i8p_ty.to_ref());
957 llvm::LLVMSetInitializer(imp, init);
958 llvm::LLVMRustSetLinkage(imp, llvm::Linkage::ExternalLinkage);
966 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
969 impl Iterator for ValueIter {
970 type Item = ValueRef;
972 fn next(&mut self) -> Option<ValueRef> {
975 self.cur = unsafe { (self.step)(old) };
983 fn iter_globals(llmod: llvm::ModuleRef) -> ValueIter {
986 cur: llvm::LLVMGetFirstGlobal(llmod),
987 step: llvm::LLVMGetNextGlobal,
992 fn iter_functions(llmod: llvm::ModuleRef) -> ValueIter {
995 cur: llvm::LLVMGetFirstFunction(llmod),
996 step: llvm::LLVMGetNextFunction,
1001 /// The context provided lists a set of reachable ids as calculated by
1002 /// middle::reachable, but this contains far more ids and symbols than we're
1003 /// actually exposing from the object file. This function will filter the set in
1004 /// the context to the set of ids which correspond to symbols that are exposed
1005 /// from the object file being generated.
1007 /// This list is later used by linkers to determine the set of symbols needed to
1008 /// be exposed from a dynamic library and it's also encoded into the metadata.
1009 pub fn find_exported_symbols(tcx: TyCtxt, reachable: &NodeSet) -> NodeSet {
1010 reachable.iter().cloned().filter(|&id| {
1011 // Next, we want to ignore some FFI functions that are not exposed from
1012 // this crate. Reachable FFI functions can be lumped into two
1015 // 1. Those that are included statically via a static library
1016 // 2. Those included otherwise (e.g. dynamically or via a framework)
1018 // Although our LLVM module is not literally emitting code for the
1019 // statically included symbols, it's an export of our library which
1020 // needs to be passed on to the linker and encoded in the metadata.
1022 // As a result, if this id is an FFI item (foreign item) then we only
1023 // let it through if it's included statically.
1024 match tcx.hir.get(id) {
1025 hir_map::NodeForeignItem(..) => {
1026 let def_id = tcx.hir.local_def_id(id);
1027 tcx.sess.cstore.is_statically_included_foreign_item(def_id)
1030 // Only consider nodes that actually have exported symbols.
1031 hir_map::NodeItem(&hir::Item {
1032 node: hir::ItemStatic(..), .. }) |
1033 hir_map::NodeItem(&hir::Item {
1034 node: hir::ItemFn(..), .. }) |
1035 hir_map::NodeImplItem(&hir::ImplItem {
1036 node: hir::ImplItemKind::Method(..), .. }) => {
1037 let def_id = tcx.hir.local_def_id(id);
1038 let generics = tcx.generics_of(def_id);
1039 let attributes = tcx.get_attrs(def_id);
1040 (generics.parent_types == 0 && generics.types.is_empty()) &&
1041 // Functions marked with #[inline] are only ever translated
1042 // with "internal" linkage and are never exported.
1043 !attr::requests_inline(&attributes)
1051 pub fn trans_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1052 analysis: ty::CrateAnalysis,
1053 incremental_hashes_map: &IncrementalHashesMap)
1054 -> CrateTranslation {
1055 // Be careful with this krate: obviously it gives access to the
1056 // entire contents of the krate. So if you push any subtasks of
1057 // `TransCrate`, you need to be careful to register "reads" of the
1058 // particular items that will be processed.
1059 let krate = tcx.hir.krate();
1061 let ty::CrateAnalysis { reachable, .. } = analysis;
1062 let exported_symbols = find_exported_symbols(tcx, &reachable);
1064 let check_overflow = tcx.sess.overflow_checks();
1066 let link_meta = link::build_link_meta(incremental_hashes_map);
1068 let shared_ccx = SharedCrateContext::new(tcx,
1071 // Translate the metadata.
1072 let (metadata_llcx, metadata_llmod, metadata) =
1073 time(tcx.sess.time_passes(), "write metadata", || {
1074 write_metadata(tcx, &link_meta, shared_ccx.exported_symbols())
1077 let metadata_module = ModuleTranslation {
1078 name: link::METADATA_MODULE_NAME.to_string(),
1079 symbol_name_hash: 0, // we always rebuild metadata, at least for now
1080 source: ModuleSource::Translated(ModuleLlvm {
1081 llcx: metadata_llcx,
1082 llmod: metadata_llmod,
1085 let no_builtins = attr::contains_name(&krate.attrs, "no_builtins");
1087 // Skip crate items and just output metadata in -Z no-trans mode.
1088 if tcx.sess.opts.debugging_opts.no_trans ||
1089 !tcx.sess.opts.output_types.should_trans() {
1090 let empty_exported_symbols = ExportedSymbols::empty();
1091 let linker_info = LinkerInfo::new(&shared_ccx, &empty_exported_symbols);
1092 return CrateTranslation {
1093 crate_name: tcx.crate_name(LOCAL_CRATE),
1095 metadata_module: metadata_module,
1098 exported_symbols: empty_exported_symbols,
1099 no_builtins: no_builtins,
1100 linker_info: linker_info,
1101 windows_subsystem: None,
1105 // Run the translation item collector and partition the collected items into
1107 let (translation_items, codegen_units) =
1108 collect_and_partition_translation_items(&shared_ccx);
1110 let mut all_stats = Stats::default();
1111 let modules: Vec<ModuleTranslation> = codegen_units
1114 let dep_node = cgu.work_product_dep_node();
1115 let (stats, module) =
1116 tcx.dep_graph.with_task(dep_node,
1117 AssertDepGraphSafe(&shared_ccx),
1118 AssertDepGraphSafe(cgu),
1119 module_translation);
1120 all_stats.extend(stats);
1125 fn module_translation<'a, 'tcx>(
1126 scx: AssertDepGraphSafe<&SharedCrateContext<'a, 'tcx>>,
1127 args: AssertDepGraphSafe<CodegenUnit<'tcx>>)
1128 -> (Stats, ModuleTranslation)
1130 // FIXME(#40304): We ought to be using the id as a key and some queries, I think.
1131 let AssertDepGraphSafe(scx) = scx;
1132 let AssertDepGraphSafe(cgu) = args;
1134 let cgu_name = String::from(cgu.name());
1135 let cgu_id = cgu.work_product_id();
1136 let symbol_name_hash = cgu.compute_symbol_name_hash(scx);
1138 // Check whether there is a previous work-product we can
1139 // re-use. Not only must the file exist, and the inputs not
1140 // be dirty, but the hash of the symbols we will generate must
1142 let previous_work_product =
1143 scx.dep_graph().previous_work_product(&cgu_id).and_then(|work_product| {
1144 if work_product.input_hash == symbol_name_hash {
1145 debug!("trans_reuse_previous_work_products: reusing {:?}", work_product);
1148 if scx.sess().opts.debugging_opts.incremental_info {
1149 println!("incremental: CGU `{}` invalidated because of \
1150 changed partitioning hash.",
1153 debug!("trans_reuse_previous_work_products: \
1154 not reusing {:?} because hash changed to {:?}",
1155 work_product, symbol_name_hash);
1160 if let Some(buf) = previous_work_product {
1161 // Don't need to translate this module.
1162 let module = ModuleTranslation {
1165 source: ModuleSource::Preexisting(buf.clone())
1167 return (Stats::default(), module);
1170 // Instantiate translation items without filling out definitions yet...
1171 let lcx = LocalCrateContext::new(scx, cgu);
1173 let ccx = CrateContext::new(scx, &lcx);
1174 let trans_items = ccx.codegen_unit()
1175 .items_in_deterministic_order(ccx.tcx());
1176 for &(trans_item, linkage) in &trans_items {
1177 trans_item.predefine(&ccx, linkage);
1180 // ... and now that we have everything pre-defined, fill out those definitions.
1181 for &(trans_item, _) in &trans_items {
1182 trans_item.define(&ccx);
1185 // If this codegen unit contains the main function, also create the
1187 maybe_create_entry_wrapper(&ccx);
1189 // Run replace-all-uses-with for statics that need it
1190 for &(old_g, new_g) in ccx.statics_to_rauw().borrow().iter() {
1192 let bitcast = llvm::LLVMConstPointerCast(new_g, llvm::LLVMTypeOf(old_g));
1193 llvm::LLVMReplaceAllUsesWith(old_g, bitcast);
1194 llvm::LLVMDeleteGlobal(old_g);
1198 // Create the llvm.used variable
1199 // This variable has type [N x i8*] and is stored in the llvm.metadata section
1200 if !ccx.used_statics().borrow().is_empty() {
1201 let name = CString::new("llvm.used").unwrap();
1202 let section = CString::new("llvm.metadata").unwrap();
1203 let array = C_array(Type::i8(&ccx).ptr_to(), &*ccx.used_statics().borrow());
1206 let g = llvm::LLVMAddGlobal(ccx.llmod(),
1207 val_ty(array).to_ref(),
1209 llvm::LLVMSetInitializer(g, array);
1210 llvm::LLVMRustSetLinkage(g, llvm::Linkage::AppendingLinkage);
1211 llvm::LLVMSetSection(g, section.as_ptr());
1215 // Finalize debuginfo
1216 if ccx.sess().opts.debuginfo != NoDebugInfo {
1217 debuginfo::finalize(&ccx);
1223 source: ModuleSource::Translated(ModuleLlvm {
1230 (lcx.into_stats(), module)
1233 assert_module_sources::assert_module_sources(tcx, &modules);
1235 symbol_names_test::report_symbol_names(tcx);
1237 if shared_ccx.sess().trans_stats() {
1238 println!("--- trans stats ---");
1239 println!("n_glues_created: {}", all_stats.n_glues_created.get());
1240 println!("n_null_glues: {}", all_stats.n_null_glues.get());
1241 println!("n_real_glues: {}", all_stats.n_real_glues.get());
1243 println!("n_fns: {}", all_stats.n_fns.get());
1244 println!("n_inlines: {}", all_stats.n_inlines.get());
1245 println!("n_closures: {}", all_stats.n_closures.get());
1246 println!("fn stats:");
1247 all_stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
1248 insns_b.cmp(&insns_a)
1250 for tuple in all_stats.fn_stats.borrow().iter() {
1252 (ref name, insns) => {
1253 println!("{} insns, {}", insns, *name);
1259 if shared_ccx.sess().count_llvm_insns() {
1260 for (k, v) in all_stats.llvm_insns.borrow().iter() {
1261 println!("{:7} {}", *v, *k);
1265 let sess = shared_ccx.sess();
1267 let exported_symbols = ExportedSymbols::compute(&shared_ccx);
1269 // Get the list of llvm modules we created. We'll do a few wacky
1270 // transforms on them now.
1272 let llvm_modules: Vec<_> =
1274 .filter_map(|module| match module.source {
1275 ModuleSource::Translated(llvm) => Some(llvm),
1280 // Now that we have all symbols that are exported from the CGUs of this
1281 // crate, we can run the `internalize_symbols` pass.
1282 time(shared_ccx.sess().time_passes(), "internalize symbols", || {
1283 internalize_symbols(sess,
1290 if tcx.sess.opts.debugging_opts.print_type_sizes {
1291 gather_type_sizes(tcx);
1294 if sess.target.target.options.is_like_msvc &&
1295 sess.crate_types.borrow().iter().any(|ct| *ct == config::CrateTypeRlib) {
1296 create_imps(sess, &llvm_modules);
1299 let linker_info = LinkerInfo::new(&shared_ccx, &exported_symbols);
1301 let subsystem = attr::first_attr_value_str_by_name(&krate.attrs,
1302 "windows_subsystem");
1303 let windows_subsystem = subsystem.map(|subsystem| {
1304 if subsystem != "windows" && subsystem != "console" {
1305 tcx.sess.fatal(&format!("invalid windows subsystem `{}`, only \
1306 `windows` and `console` are allowed",
1309 subsystem.to_string()
1313 crate_name: tcx.crate_name(LOCAL_CRATE),
1315 metadata_module: metadata_module,
1318 exported_symbols: exported_symbols,
1319 no_builtins: no_builtins,
1320 linker_info: linker_info,
1321 windows_subsystem: windows_subsystem,
1325 fn gather_type_sizes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
1326 let layout_cache = tcx.layout_cache.borrow();
1327 for (ty, layout) in layout_cache.iter() {
1329 // (delay format until we actually need it)
1330 let record = |kind, opt_discr_size, variants| {
1331 let type_desc = format!("{:?}", ty);
1332 let overall_size = layout.size(tcx);
1333 let align = layout.align(tcx);
1334 tcx.sess.code_stats.borrow_mut().record_type_size(kind,
1342 let (adt_def, substs) = match ty.sty {
1343 ty::TyAdt(ref adt_def, substs) => {
1344 debug!("print-type-size t: `{:?}` process adt", ty);
1348 ty::TyClosure(..) => {
1349 debug!("print-type-size t: `{:?}` record closure", ty);
1350 record(DataTypeKind::Closure, None, vec![]);
1355 debug!("print-type-size t: `{:?}` skip non-nominal", ty);
1360 let adt_kind = adt_def.adt_kind();
1362 let build_field_info = |(field_name, field_ty): (ast::Name, Ty), offset: &layout::Size| {
1363 match layout_cache.get(&field_ty) {
1364 None => bug!("no layout found for field {} type: `{:?}`", field_name, field_ty),
1365 Some(field_layout) => {
1366 session::FieldInfo {
1367 name: field_name.to_string(),
1368 offset: offset.bytes(),
1369 size: field_layout.size(tcx).bytes(),
1370 align: field_layout.align(tcx).abi(),
1376 let build_primitive_info = |name: ast::Name, value: &layout::Primitive| {
1377 session::VariantInfo {
1378 name: Some(name.to_string()),
1379 kind: session::SizeKind::Exact,
1380 align: value.align(tcx).abi(),
1381 size: value.size(tcx).bytes(),
1387 WithDiscrim(&'a layout::Struct),
1388 NoDiscrim(&'a layout::Struct),
1391 let build_variant_info = |n: Option<ast::Name>, flds: &[(ast::Name, Ty)], layout: Fields| {
1392 let (s, field_offsets) = match layout {
1393 Fields::WithDiscrim(s) => (s, &s.offsets[1..]),
1394 Fields::NoDiscrim(s) => (s, &s.offsets[0..]),
1396 let field_info: Vec<_> = flds.iter()
1397 .zip(field_offsets.iter())
1398 .map(|(&field_name_ty, offset)| build_field_info(field_name_ty, offset))
1401 session::VariantInfo {
1402 name: n.map(|n|n.to_string()),
1404 session::SizeKind::Exact
1406 session::SizeKind::Min
1408 align: s.align.abi(),
1409 size: s.min_size.bytes(),
1415 Layout::StructWrappedNullablePointer { nonnull: ref variant_layout,
1418 discrfield_source: _ } => {
1419 debug!("print-type-size t: `{:?}` adt struct-wrapped nullable nndiscr {} is {:?}",
1420 ty, nndiscr, variant_layout);
1421 let variant_def = &adt_def.variants[nndiscr as usize];
1422 let fields: Vec<_> = variant_def.fields.iter()
1423 .map(|field_def| (field_def.name, field_def.ty(tcx, substs)))
1425 record(adt_kind.into(),
1427 vec![build_variant_info(Some(variant_def.name),
1429 Fields::NoDiscrim(variant_layout))]);
1431 Layout::RawNullablePointer { nndiscr, value } => {
1432 debug!("print-type-size t: `{:?}` adt raw nullable nndiscr {} is {:?}",
1433 ty, nndiscr, value);
1434 let variant_def = &adt_def.variants[nndiscr as usize];
1435 record(adt_kind.into(), None,
1436 vec![build_primitive_info(variant_def.name, &value)]);
1438 Layout::Univariant { variant: ref variant_layout, non_zero: _ } => {
1439 let variant_names = || {
1440 adt_def.variants.iter().map(|v|format!("{}", v.name)).collect::<Vec<_>>()
1442 debug!("print-type-size t: `{:?}` adt univariant {:?} variants: {:?}",
1443 ty, variant_layout, variant_names());
1444 assert!(adt_def.variants.len() <= 1,
1445 "univariant with variants {:?}", variant_names());
1446 if adt_def.variants.len() == 1 {
1447 let variant_def = &adt_def.variants[0];
1448 let fields: Vec<_> = variant_def.fields.iter()
1449 .map(|field_def| (field_def.name, field_def.ty(tcx, substs)))
1451 record(adt_kind.into(),
1453 vec![build_variant_info(Some(variant_def.name),
1455 Fields::NoDiscrim(variant_layout))]);
1457 // (This case arises for *empty* enums; so give it
1459 record(adt_kind.into(), None, vec![]);
1463 Layout::General { ref variants, discr, .. } => {
1464 debug!("print-type-size t: `{:?}` adt general variants def {} layouts {} {:?}",
1465 ty, adt_def.variants.len(), variants.len(), variants);
1466 let variant_infos: Vec<_> = adt_def.variants.iter()
1467 .zip(variants.iter())
1468 .map(|(variant_def, variant_layout)| {
1469 let fields: Vec<_> = variant_def.fields.iter()
1470 .map(|field_def| (field_def.name, field_def.ty(tcx, substs)))
1472 build_variant_info(Some(variant_def.name),
1474 Fields::WithDiscrim(variant_layout))
1477 record(adt_kind.into(), Some(discr.size()), variant_infos);
1480 Layout::UntaggedUnion { ref variants } => {
1481 debug!("print-type-size t: `{:?}` adt union variants {:?}",
1483 // layout does not currently store info about each
1485 record(adt_kind.into(), None, Vec::new());
1488 Layout::CEnum { discr, .. } => {
1489 debug!("print-type-size t: `{:?}` adt c-like enum", ty);
1490 let variant_infos: Vec<_> = adt_def.variants.iter()
1491 .map(|variant_def| {
1492 build_primitive_info(variant_def.name,
1493 &layout::Primitive::Int(discr))
1496 record(adt_kind.into(), Some(discr.size()), variant_infos);
1499 // other cases provide little interesting (i.e. adjustable
1500 // via representation tweaks) size info beyond total size.
1501 Layout::Scalar { .. } |
1502 Layout::Vector { .. } |
1503 Layout::Array { .. } |
1504 Layout::FatPointer { .. } => {
1505 debug!("print-type-size t: `{:?}` adt other", ty);
1506 record(adt_kind.into(), None, Vec::new())
1512 #[inline(never)] // give this a place in the profiler
1513 fn assert_symbols_are_distinct<'a, 'tcx, I>(tcx: TyCtxt<'a, 'tcx, 'tcx>, trans_items: I)
1514 where I: Iterator<Item=&'a TransItem<'tcx>>
1516 let mut symbols: Vec<_> = trans_items.map(|trans_item| {
1517 (trans_item, trans_item.symbol_name(tcx))
1520 (&mut symbols[..]).sort_by(|&(_, ref sym1), &(_, ref sym2)|{
1524 for pair in (&symbols[..]).windows(2) {
1525 let sym1 = &pair[0].1;
1526 let sym2 = &pair[1].1;
1529 let trans_item1 = pair[0].0;
1530 let trans_item2 = pair[1].0;
1532 let span1 = trans_item1.local_span(tcx);
1533 let span2 = trans_item2.local_span(tcx);
1535 // Deterministically select one of the spans for error reporting
1536 let span = match (span1, span2) {
1537 (Some(span1), Some(span2)) => {
1538 Some(if span1.lo.0 > span2.lo.0 {
1544 (Some(span), None) |
1545 (None, Some(span)) => Some(span),
1549 let error_message = format!("symbol `{}` is already defined", sym1);
1551 if let Some(span) = span {
1552 tcx.sess.span_fatal(span, &error_message)
1554 tcx.sess.fatal(&error_message)
1560 fn collect_and_partition_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>)
1561 -> (FxHashSet<TransItem<'tcx>>,
1562 Vec<CodegenUnit<'tcx>>) {
1563 let time_passes = scx.sess().time_passes();
1565 let collection_mode = match scx.sess().opts.debugging_opts.print_trans_items {
1567 let mode_string = s.to_lowercase();
1568 let mode_string = mode_string.trim();
1569 if mode_string == "eager" {
1570 TransItemCollectionMode::Eager
1572 if mode_string != "lazy" {
1573 let message = format!("Unknown codegen-item collection mode '{}'. \
1574 Falling back to 'lazy' mode.",
1576 scx.sess().warn(&message);
1579 TransItemCollectionMode::Lazy
1582 None => TransItemCollectionMode::Lazy
1585 let (items, inlining_map) =
1586 time(time_passes, "translation item collection", || {
1587 collector::collect_crate_translation_items(&scx, collection_mode)
1590 assert_symbols_are_distinct(scx.tcx(), items.iter());
1592 let strategy = if scx.sess().opts.debugging_opts.incremental.is_some() {
1593 PartitioningStrategy::PerModule
1595 PartitioningStrategy::FixedUnitCount(scx.sess().opts.cg.codegen_units)
1598 let codegen_units = time(time_passes, "codegen unit partitioning", || {
1599 partitioning::partition(scx,
1600 items.iter().cloned(),
1605 assert!(scx.tcx().sess.opts.cg.codegen_units == codegen_units.len() ||
1606 scx.tcx().sess.opts.debugging_opts.incremental.is_some());
1608 let translation_items: FxHashSet<TransItem<'tcx>> = items.iter().cloned().collect();
1610 if scx.sess().opts.debugging_opts.print_trans_items.is_some() {
1611 let mut item_to_cgus = FxHashMap();
1613 for cgu in &codegen_units {
1614 for (&trans_item, &linkage) in cgu.items() {
1615 item_to_cgus.entry(trans_item)
1616 .or_insert(Vec::new())
1617 .push((cgu.name().clone(), linkage));
1621 let mut item_keys: Vec<_> = items
1624 let mut output = i.to_string(scx.tcx());
1625 output.push_str(" @@");
1626 let mut empty = Vec::new();
1627 let mut cgus = item_to_cgus.get_mut(i).unwrap_or(&mut empty);
1628 cgus.as_mut_slice().sort_by_key(|&(ref name, _)| name.clone());
1630 for &(ref cgu_name, linkage) in cgus.iter() {
1631 output.push_str(" ");
1632 output.push_str(&cgu_name);
1634 let linkage_abbrev = match linkage {
1635 llvm::Linkage::ExternalLinkage => "External",
1636 llvm::Linkage::AvailableExternallyLinkage => "Available",
1637 llvm::Linkage::LinkOnceAnyLinkage => "OnceAny",
1638 llvm::Linkage::LinkOnceODRLinkage => "OnceODR",
1639 llvm::Linkage::WeakAnyLinkage => "WeakAny",
1640 llvm::Linkage::WeakODRLinkage => "WeakODR",
1641 llvm::Linkage::AppendingLinkage => "Appending",
1642 llvm::Linkage::InternalLinkage => "Internal",
1643 llvm::Linkage::PrivateLinkage => "Private",
1644 llvm::Linkage::ExternalWeakLinkage => "ExternalWeak",
1645 llvm::Linkage::CommonLinkage => "Common",
1648 output.push_str("[");
1649 output.push_str(linkage_abbrev);
1650 output.push_str("]");
1658 for item in item_keys {
1659 println!("TRANS_ITEM {}", item);
1663 (translation_items, codegen_units)